Process for the dyeing of copolymers of



3 079 210 PROCESS FQR THE DY EIP IG F CGPOLYMERS 0F ACRYLQNITRILE ANDVINYL-ACETATE 0R VlNYL-PYRIDINE Adam Mikula, Basel, witzerland, assignorto Sandoz Ltd. (also known as Sandoz A.G.), Basel, Switzerland, a Swissfirm No Drawing. Filed Dec. 21, 1959, Ser. No. 860,692 17 Claims. (Cl.8-55) The dyeing of the copolymer fibers which are produced bycopolymerization of 8090% acrylonitrile and 20-10% vinyl acetate orvinyl-pyridine (e.g. the copolymer of 85 acrylonitrile and vinyl acetateor vinylpyridine manufactured by the Chemstrand Corporation, Decatur,Alabama, U.S.A., under the registered trade mark Acrilan) has presenteda difficult technical problem which still awaits a satisfactorysolution. The problem is the same in all the forms in which the fibersare dyed, whether as woven fabric, knitwear, yarn, hank or package, orin blends with other fibers, for example wool.

This invention relates to a process for the dyeing of copolymer fiberswhich are produced by copolymerization of 8090% acrylonitrile and -10%vinyl acetate or vinylpyridine, more particularly of 85 acrylonitrileand 15 vinyl acetate or vinylpyridine, and for the dyeing of blends ofthese and other fibers, e.g. wool, using acid wool, chrome or 1:2 metalcomplex dyestufiis, and particularly 1:2 cobalt and 1:2 chromiumdyestuffs. The process consists in treating the material either before,during or after dyeing with a highly sulfonated unsaturated fatty acidof higher molecular weight or with an ester of such an acid, e.g. highlysulfonated oleic acid with a degree of sulfonation of 99% or a highlysulfonated castor oil such as sulforicinate with a degree of sulfonationof 80%, and carrying out the actual dyeing process in a medium acidifiedwith formic, acetic or sulfuric acid.

When the process is performed simultaneously with dyeing, the dyebath isset with a highly sulfonated unsaturated fatty acid of higher molecularweight or with an ester of such an acid and the amount of acid necessaryto give a good degree of bath exhaustion. The goods are entered, thedyebath brought to the boil and dyeing continued at the boil for 1 to 2hours as required. The dyeings obtained are full, penetrated and ofbrilliant shade, and show good light fastness and very good wet fastnessproperties (eg washing, water, perspiration, milling, crocking).

Equally good results are obtained when the goods are treated beforedyeing with a highly sulfon-ated unsaturated fatty acid of highermolecular weight or with an ester of such an acid. After treatment ofthe dyed goods with an acid or ester of the said type substantiallyimproves the wet fastness properties without, of course, reducing thedepth of the dyeing.

When Acrilan is dyed without the addition of a highly sulfonatedunsaturated fatty acid of higher molecular weight or of an ester of suchan acid, only the surface of the fiber is dyed (ring dyeing) andconsequently the dyeings are weaker, duller, less fast to light and insome cases less fast to wet agencies than the dyeings obtained accordingto the present process.

When dyeing is carried out in high temperature dyeing machines underpressure, the dyeing times can be considerably reduced byt he additionof a highly sulfonated unsaturated fatty acid of higher molecular weightor of an ester of such an acid.

In the following examples the parts are by weight the percentages arecalculated on the Weight of the goods 3,079,210 Patented Feb. 26, 1963and the temperatures are in degrees centigrade. The dyestuffs used arelisted in the Colour Index, vol. I, 2nd edition, 1956, on the pagesgiven in brackets after the names.

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EXAMPLE 1 100 parts of a 100% Acrilan fabric are dyed in 5000 parts of adyeliquor containing the following ingredients:

2 parts of Lanasyn Brilliant Green BL (1324),

25 parts of a sulforicinate with a degree of sulfonation of and 2 partsof 80% acetic acid.

The fabric is entered in the dyebath at 50 and the temperature increasedto 98100 in 30 minutes. 2 parts of formic acid are added and dyeingcontinued for 1 to 2 hours at the same temperature. The fabric is dyedto an attractive green shade possessing good light fastness and verygood washing fastness.

The 2 parts of 85% formic acid can be replaced by 3 to 4 parts of 80%acetic acid.

A dyeing produced under identical conditions without the addition ofsulforicinate shows very poor washing fastness and in addition is dulland weak.

In place of Lanasyn Brilliant Green BL (1324) the following dyestuffscan be used:

Xylene Milling Yellow 36L (1036), Xylene Acid Milling Orange 2G (1081),Sulfonine Scarlet GWL (1140), Brilliant Alizarine Milling Red FBL(1155), Brilliant Alizarine Milling Violet FBL (1213), Alizarine MillingBlue SL (1295), Brilliant Alizarine Milling Blue BL (1265), G (1286),2RL (1285), RWL (1288), FGL

(1292/3) and the red dyestutf of Example 2 of Swiss Patent 316,753.

EXAMPLE 2 A dyeliquor is prepared with:

6000 parts of water,

2 parts of Lanasyn Brown RL (1340,

25 parts of a sulforicinate with a degree of sulfonation 2 parts of 80%acetic acid,

2 parts of 85% formic acid and 2 parts of 66% sulfuric acid.

The dyeing can also be carried out in a dyebath acidi fied with 2.5 to 3parts of 66% sulfuric only or with 3 to 4 parts of 85% formic acid only.

In place of Lanasyn Brown RL (1340) the following dyestuffs can be used:Lanasyn Yellow 3GL (1048),

Yellow GLN (1049), Yellow 2RL (1086), Orange RLN (1087), Red ZGL (1182),Red BL (1182), Bordeaux BL (1183), Brown 3RL (1341), Dark Violet RL(1221) and Grey BL (1397).

EXAMPLE 3 The dyebath is set with the ingredients given in Example 2,and dyeing is carried out in a high temperature laboratory dyeingmachine for 30 minutes at brown dyeing is well penetrated and has goodfastness to light and washing. The same good results are obtained whenthe dyeing is carried out at 110 [for about 45 minutes or at for about20-25 minutes.

The-

3 EXAMPLE 4 100 parts of 100% Acrilan fabric are treated for 30 minuteswith a boiling solution of 4 parts of a sulforicinate with a degree ofsulfonation of 80% in 6000 parts of water. The well impregnated fabricis then rinsed with water and entered in a dyebath at 50 made up with6000 par-ts of water, 2 parts of 80% acetic acid and 2 parts of LanasynGrey BL (1397). The bath is brought to 100-in about, 30 minutes,15 partsof 10% formic acid are added and dyeing continued for 1 hour at 100. Thedyed fabric is "removed, rinsed with water and dried. A dyeing of fulldepth is obtained which is notable for the good penetration of dyestufiand its good light fastness and very good fastness to washing, millingand perspiration.

The preliminary treatmentcan also be carried out at 80.

The same dyeing procedure with the omission of the preliminary treatmentresults is a dyeing of light depth which is not penetrated and lackswashing fastness.

With the process described, in this example full, penetrated dyeingsfast to light and wet treatments can be obtained with the dyestuffsnamed in Examples 1 and 2.

EXAMPLE I An Acrilan fabric is dyed with. 2% Lanasyn Brown- RL (1340 inan acid dyebath for 1 hour at 100. The dyeing is thin and dull in shadeand has insufficient Washing fastness. It is treated for 30 minutes in abath at 98 9 9 containing 0.5 part of a highly sulfonated castor oil; in1000 partsof water (goods to liquor ratio 1:60), upon which a moreattractive dyeing of the same depth is obtained but with much better Wetfastness properties.

Inthe same way the wet fastn'essproperties ofqdyeings onAcrilan fabricproduced with thedyestnfls named in Examples 1, 2' and 5 without theaddition of a highly sulfonated ester of a higher molecular unsaturatedfatty acid can be substantially improved by an aftertreatment of theabove nature.

EXAMPLE 6 100 parts of an A-crilan-wool fabric, blended in the ratio of1:1 or 3:2 are entered in a bath of 5000 parts of water,

25 parts of a sulforicinate with adegree of sulfonation of 80% and 2parts of 80% formic acid.

Thegbath is brought to the boil and after boiling for 15-20 minutes coldwater is run in to cool it to room temperature. Teh impregnated fabricis removed, rinsed and entered in a dyebath set with 5000 parts ofwater,

2'parts of Lanasyn Brown RL (1340),

5 parts of a sulforicinate with'a degree of sulfonation of 80% and 2parts-of 80% acetic acid.

The dyebath is brought to the boil in 30 minutes and maintained at theboil for 45 minutes. 2 parts of 66% sulfuric acid 'are added and dyeingcontinued for 2 hours atthe'boil. The fabric is then removed, rinsed anddried. The Acrilan and the wool components are dyed to equal depth inthe same attractive brown shade (tone-in-tone dyeing). Withoutpreliminary treatment and without the addition of sulforicinate in thedyebath the fabric is not penetrated by the dyestutf and the wool isdyed more heavily than the Acrilan, the dyeing as a whole being dull inshade and without fastness to washing.

In the following table some further dyestuffs are listed which can beapplied according to the procedures described in Examples 1 to 6 andgive dyeings of particularly good light fastness on Acrilan. Column 1contains the commercial names of the dyestufis, column 2 the page in theColour Index, vol. I, 2nd edition, on which they are listed anddescribed, and column 3 the shade of the dyeing on Acrilan.

Having thus disclosed the invention what I claim'is:

1. Process for dyeing copolymer and a blend containing same,.saidcopolymer being composed of from to acrylonitrile and from 20 ,to 10% ofa polymerizable compound selected from the group consisting of vinylacetate and vinyl-pyridine, with a dyestuff selected from the groupconsisting of 1:2-cobalt dyestufi, 1:2- chromium dyestulf, and aciddyestufi without metallizable groups, in shades fast to wet treatments,which consists in treating a member selected from the group consistingof the copolymer and the blend with a sulforicinate of 80% sulfonationdegree, and carrying out the actual.

dyeing in an acidified medium.

2. A process according to claim '1, wherein the treatment is carried outbefore dyeing.

3. A process according to claim 1, wherein the treatment is carried outduringdyeing.

4. A process according to claiml, wherein the treatment is carried outafter dyeing.

5. A process according to claim 1, whercin the treat: ment is carriedout at elevated temperatures.

6. A process according to claim 1, wherein the treatment is carried outat temperatures ranging from .80 to.

'7. A process according to claim 1, wherein the treatment is. carriedout in a mediumacidified with formic acid.

' '8. A process according to claim ,1, wherein the treatment is carriedout in a medium acidified with acetic acid.

. 9. A process according to claim 1, wherein the treatment is carried.out in a medium acidified with sulfuric acid.

10. A process according to claim 1, wherein the treatment is carried outin a medium acidified with a mixture of acids.

11. A process for dyeing with acid dyestufi from 80/20 to 90/10copolymer of acrylonitrile with the member selected from the groupconsisting of vinyl acetate and vinyl pyridine, whichprocess consistsessentially of contacting the copolymer with a sulforicinate of 80% sulfonation degree and carrying out the actual dyeing in an acidifiedmedium.

7 12. A process for dyeing in shades fast to wet treatments with aciddyestufi' from 80/20 to 90/10 copolymers of acrylonitrile with a memberselected from the group consisting of vinyl acetate and vinyl pyridine,which process consists essentially of contacting the copolymer with. asulforicinate of 80% sulfonation degree and carrying out the actualdyeing in an acidified medium.

13. A process for dyeing in shades fast to wet treatments with 1:2cobalt complex dyestuff from 80/20 to 90/ 10 copolymers of acrylonitrilewith a member selected from the group consisting of vinyl acetate andvinyl pyridine, which process consists essentially of contacting thecopolymer with a sulforicinate of 80% sulfonation degree and carryingout the actual dyeing in an acidified medium.

14. A process for dyeing in shades fast to wet treatments with 1:2chromium complex dyestuff from 80/20 to 90/ copolymers of acrylonitrilewith a member selected from the group consisting of vinyl acetate andvinyl pyridine, which process consists essentially of contacting thecopolymer with a sulforicinate of 80% sulfonaticn degree and carryingout the acutal dyeing in an acidified medium.

15. 8-0/20 to 90/10 copolymer of acrylonitrile with a member selectedfrom the group consisting of vinyl acetate and vinyle pyridine dyed inan acidified medium with an acid dyestufi and intimately contacted witha member selected from the group consisting of a sulforicinate of 80%sulfonation degree, the shade of said copolymer being fast to wettreatment.

16. 80/20 to 90/10 copolymer of acrylonitrile with a member selectedfrom the group consisting of vinyl acetate and vinyl pyridine dyed in anacidified medium with a 1:2 metal complex dyestufi said metal being amember selected from the group consisting of cobalt and chromium andintimately contacted with a sulforicinate 6 of sulfonation degree, theshade of said copolymer being fast to wet treatment 17. A memberselected from the group consisting of copolymer composed of from 80 toacrylonitrile and from 20 to 10% of a polymerizable compound selectedfrom the group consisting of vinyl acetate and vinylpyridine and blendscontaining such poloymers dyed according to the process claimed in claim1.

References Cited in the file of this patent UNITED STATES PATENTSKhachoyan et a1 May 17, 1960 OTHER REFERENCES

1. PROCESS FOR DYEING COPOLYMER AND A BLEND CONTAINING THE SAME, SAIDCOPOLYMERR BEING COMPOSED OF FROM 80 TO 90% ACRYLONITRILE AND FROM 20 TO10% OF A POLYMERIZABLE COMPOUND SELECTED FROM THE GROUP CONSISTING OFVINYL ACETATE AND VINYL-PYRIDINE, WITH A DYESTUFF SELECTED FROM THEGROUP CONSISTING OF 1:2-COBALT DYESTUFF, 1:2CHROMIUM DYESTUFF, AND ACIDDYESTUFF WITHOUT METALLIZABLE GROUPS, IN SHADES FAST TO WET TREATMENTS,WHICH CONSISTS IN TREATING A MEMBER SELECTED FROM THE GROUP CONSISTINGOF THE COPOLYMER AND THE BLEND WITH A SULFORICINATE OF 80% SULFONATIONDEGREE, AND CARRYING OUT THE ACTUAL DYEING IN AN ACIDIFIED MEDIUM.